Resin carrying aldehyde bound chelator



United States Patent 3,313,779 RESIN CARRYING ALDEHYDE BOUND CHELATOR LeRoy A. White, Root Road, Somers, Conn. 05071 No Drawing. Filed Apr. 6,1964, Ser. No. 357,811 20 Claims. (Cl. 26tl59) This is acontinuation-in-part of application Ser. No. 765,924, filed Oct. 8,1958, and now abandoned.

The present invention relates to ion exchange resins, and, moreparticularly, to ion exchange resins which comprise a chelating moleculeattached to a resin or polymer through the reaction of an aldehyde typecompound.

Ion exchange resins are known and are commercially available for avariety of uses. Many commercial operations require water or watersolutions which are substantially free of trivalent cations, such asferric ions; monovalent cations, such as sodium, however, are often notobjectionable in such operations. The prior art methods of removingmultivalent cations from aqueous solutions embody the followingmaterials:

(1) Sulfated or carboxylated insoluble resins;

(2) inorganic siliceous materials;

(3) sequestering agents.

These materials suffer from the following defects:

1) Sulfated and carboxylated insoluble resins, such as sulfatedstyrene/divinyl benzene copolymers, sulfated coal and crosslinkedpolyacrylic acid, indiscriminately remove all cations from solutionrather than selectively removing only the multivalent cations.Unnecessary removal of monovalent ions causes the unnecessary expense ofregenerating the ion exchange resin more frequently than would berequired if only the multivalent ions were removed.

(2) Inorganic siliceous materials, such as zeolites, do not iri generalsuffer from the aforementioned defect. However, their efiiciency inpreferentially removing multivalent ions is not sufliciently high tojustify their use in many processes where they have other disadvantages,e.g., silicates are not used in metals purification procedures since anyattempt to leach out absorbed metals will usually destroy the silicate.In addition, the inorganic siliceous materials are readily soluble inwater unless the pH is carefully controlled and thus cause proceduraldifiiculties.

(3) sequestering agents, such as ethylene diamine tetraacetic acid, areuseful in many operations where it is necessary to remove multivalentcations. However, such sequestering agents are preferably not used inthe manufacture of beverages, such as wine or beer, to prevent theformation of precipitates caused by multivalent cations, since thesequestering agents effectively remove calcium from teeth. Also, wherethe multivalent cations can enter into chemical reactions, thesequestering agents are of limited effectiveness because they willcontinuously release the cation to maintain the reaction equilibrium asthe cations in solution are consumed.

It is, therefore, an object of this invention to provide ion exchangeresins which will remove multivalent cations from solutions inpreference to monovalent ions.

It is another object of the present invention to provide a simple,convenient and effective method of synthesis of a sequestering ionexchange resin.

It is another object to produce insoluble resins having far greateraifinity for multivalent ions than for monovalent ions which do notsuifer from the defects of the prior art, such as those mentioned above.

It is another object of the present invention to provide ion exchangechelating resins by the reaction of an aldehyde type compound.

These and other objects and the nature and advantages of the presentinvention will be apparent from the following description.

The objects of this invention are attained by attaching a sequesteringgrouping to a resin or resinifiable material through the intermediatereaction of one component with an aldehyde type compound. This may beaccomplished in a number of Ways, such as:

1) By reacting an aldehyde type compound with a sequestering agent andthen reacting the product with a resin; I

(2) By reacting an aldehyde type compound with a resin and then reactingthe resultant active resin with a sequestering agent;

(3) By reacting a resin previously provided with free reactive methylolor methoxy groups with a sequestering agent, procedure (3) being similarto that of procedure (2);

(4) By reacting a sequestering agent with a low molecular weightresinifiable material or monomer, preferably of the aldehyde type, andthen polymerizing such as by a homopolymerization, a copolymerization,or a condensation reaction;

(5) By carrying out any of the preceding operations and thencrosslinking with heat, acid, or another material; and

(6) By forming a cross-linked resin with free inactive methylol-groupsthereon and reacting such resin with a sequestering agent, the fiveprevious operations being preferred to this one.

The sequestering agent utilized in the present invention must bealdehyde-reactive and comprise amino, ether, and mixed amino-ether acidshaving generally two or three amino, ether, or amino-ether coordinatinggroups, three or more acid groups (i.e., carboxyl, phosphonic, sulfonic,and/or hydroxyl), and a multiplicity of methylene groups between theacid and coordinating groups so arranged that three or more cyclicalstructures may be formed with the absorbed trivalent metal during use ofthe resin. Each of these cyclical structures should contain from 5 to 7units including the metal, the coordinating group and the acid group. Asan example a cyclical group in ethylene diamine tetraacetic acid isshown:

t e 0 CH2 where Me is the trivalent metal.

In each case it is essential in the final product, whether cross-linkedor not, that the sequestering groupings be J between two other segments,it ability to chelate a metallic ion is seriously hampered.

The sequestering agents useful in the present invention fall within thegeneral formula:

J(CXY) (CXY) (CXY) K wherein J is selected from the group consisting ofQ E N -(CXY),N F G F O-M, and -OT, wherein X is selected from the groupconsisting of H and (CH COOH; wherein Y is selected from the groupconsisting of H, COOI-I, and OH; wherein a, b, and c are integers offrom 0 to 1; wherein K is selected from the same group as I, but is adifferent member and wherein and O-M are never in the same compoundtogether;

wherein E, F, and G are selected from the group consisting of H, CHCOOH, CH(COOH) CH CH OH, CH CH OCH CH OH (CHYM wherein p is an integerof from 0 to 2; wherein M is selected from the group consisting ofwherein T is selected from the group consisting of 00011 ()H COOH andand wherein A, B and D are selected from the group JOOH consisting of H,COOH,

and not more than one unit per sequestering molecule of (CHY) -OM amongA, B and D.

An exception to the general formula, which is also useful, is thesequestering agent amino diacetic acid.

It is essential that these compounds be aldehydereactive and contain atleast one of the groups Some of the specific sequestering agents fallingWithin the above general formula are: ethylene diamine triacetic acid;ethylene diamine diacetic acid; N-mono-ethoxy ethylene diamine diaceticacid; ethylene diamine di-(O- hydroxy-phenyl acetic acid); ethylenediamine diacetic acid methylene phosphonic acid; ethylene diarnineacetic acid dimethylene phosphonic acid; diethylene-triamine tetraceticacid; ethylene diamine diacetic acid ethylene sulfonic acid; diethyleneglycol dimalonate ether; ethylene diamine acetic acid diethylenesulfonic acid;

COOH 0H CH-O-CH-CHr-O HzC-COOH HOOC-C-O(CHz)z-NH HQCCOOH CHaCOOH and$0011 (lJOOH O-CHz-CH-CHz-O These and the many other sequestering agentsfalling within the general formula are reacted to form chelating resinsthrough an intermediate aldehyde type reaction.

The aldehyde type compounds used in the present invention as a means offorming a linkage between the resin or resinifiable material and thesequestering agent are compounds which engage in the same type of re-These compounds include the aldehydes, including the mono-, diandtri-functional aldehydes having no greater than 54 carbon atoms; thereactive methylol compounds, i.e. those activated by a ring structure ornitrogen; the reactive methoxy compounds (viz. methoxy methylol ormethyl methylol); compounds which revert to aldehyde form in acid media;and low molecular weight resinifiable materials having free reactivemethylol groups thereon. However, the lower the molecular Weight of thealdehyde type compound used to bond the sequestering agent to the resin,the better will be the overall ion exchange capacity of the finalchelating resin, unless the aldehyde type compound itself can beresinified or polymerized into a high molecular weight resin, such as byco-polymerization, condensation with another material, or bycross-linking with heat or acid.

Some of the aldehydes which fall within the broad group of aldehyde typecompounds useful in the present invention are: formaldehyde,acetaldehyde, .glyoxyl; glutaraldehyde, pyruvic aldehyde,cinnamaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde,valeraldehyde, citral, acrolein, crotonaldehyde, mucochloric acid,3-cyclohexene-l-carboxaldehyde, 3-(methylthio) propionaldehyde,benzaldehyde, furfural, piperonal, p-chlorobenzaldehyde, napthaldehyde,etc.

Materials which revert to aldehydes in acid media include: bisnlfiteaddition products such as formaldehyde bisulfite and acetaldehydebisulfite; cyclic aldehydes such as paraldehyde; paraformaldehyde;ammonia adducts such as acetaldehyde-ammonia; hemiacetals such asethanol-formaldehyde; and acetals such as acetaldehyde diethyl acetal.

Methylol and methoxy compounds useful as aldehyde type compounds, alsolater referred to as aldehyde compounds, include: phenolic methylolssuch as trimethylol phenol, dimethylol phenol, low-molecular weightphenol formaldehyde polymers, and acetaldehyde-phenol; methyllolmelamines such as hexamethylol melamine, hexamethoxy methyl melamine,low-molecular weight melamine-aldehyde polymers, low-molecular weightbutylatedformaldehyde-melamine; methylol ureas such as dimethylol urea,low-molecular weight urea polymers, dimethylol thiourea andlow-molecular weight methanolbutanol-formaldehyde urea resin; andmethylol anilines such as low-molecular weight polymers ofaniline-formaldehyde and phenol-aniline-formaldehyde.

The resinous or resinifiable materials useful in the presentinventionwhether (1) already polymerized when reacted with the aldehydetype compound or the aldehydesequestering agent product or (2) in lowmolecular or monomeric form prior to resinification or polymerization tohigher molecular weight, such as by copolymerization, condensation withanother material or cross-linkingmust be aldehyde-reactive, capable ofbeing waterinsolubilized, and contain phenoxyl, imino, amino, and/orhydroxyl groupings. As indicated above, if the resin or resinifiablematerial contains free reactive methylol groups extending from theresin, such methylol groups will act as the aldehyde bonding means forattaching the sequestering agent to the resin or resinifiable materialwithout a third reactant.

Specific resins, monomers and/ or resinifiable materials useful in thepresent invention include phenol-formaldehyde, olyethylenimine,aniline-formaldehyde, melamineformaldehyde, urea formaldehyde, thioureaaldehyde, polyvinyl benzyl amine, polyvinyl alcohol,phenol-formaldehyde-polyvinyl alcohol resin matrix,phenol-anilineformaldehyde, methylcellulose, cellulose monoacetate,methyl methylol derivative of 6,6 nylon, methyl methylol derivative of 6nylon, etc.

In the preferred embodiments the above aldehydereactive resins which arealso hydrophilic, such as polyvinyl alcohol, methyl cellulose andcellulose monoacetate, are preferably utilized in admixture with theother above resins not water soluble in proportions of no greater than35% and preferably in proportions around depending on the resinproperties desired between Wet strength, leaching rate and brittleness.One such mixture is the above-mentionedphenol-formaldehyde-polyvinyl-alcohol resin matrix. This does not meanto say that the aldehydereactive hydrophilic resins cannot be usedalone, but only that it is preferred that they be mixed with thehydrophobic resins.

Generally, after the formation of the resin containing side chainscomprising sequestering groupings, it is desirable to cross-link theresin to obtain a final insoluble and cross-linked ion exchangechelating resin. This can be accomplished in a number of ways dependingon the nature of the resin itself. Thus, a phenol-formaldehydesequestering resin may be cross-linked by the addition of acid orfurther aldehyde and heating. Polyethylenimine may be cross-linked withepichlorohydn'n. Essentially, the resins may be cross-linked in mannersknown in the art. If an excess of aldehyde type compound is used overthat required to link the sequesteringagent to the resin, this excessmay act to cross-link the resin.

Resins previously cross-linked and having free reactive methylol groupsthereon may also react with the aldehyde reactive sequestering agents.However, since the sequestering agent cannot readily penetrate theinterior of the cross-linked resin, the reaction takes place essentiallyon the surface of the resin giving a sequestering resin with a lowerchelating ability.

The following examples are intended only to illustrate the invention andare not intended as being limitative in any way.

Example 1 As a typical example, a sequestering material is prepared byreacting 2 moles of salicylic acid with 1 mole of epichlorohydrin in analkaline medium to form the sequestering agent:

i? (30H (TECH This compound is then reacted further in alkaline mediawith formaldehyde. This methylol derivative l OOH C i ii i CH -OOOH(IJOOH 7 8 The resion is found to be an excellent ion exchange Example 4chelatmg resm' Following the procedure of Example 1, 1.05 moles of 2Example pyruvic aldehyde are reacted with 1 mole of the sequester- Asanother example, diethylene glycol is reacted with ing agent ethylenediamine triacetic acid to yield the lithium and then reacted furtherwith mono-bromo-diethproduct yl malonate. The resulting material,diethylene glycol CH3 dimalonate ether, is then hydrolyzed with causticand in a mildly alkaline media is reacted with a slight excess ofglutaraldehyde at 5 C. Polyethylenimine is then added(H000CH1)2N(CH2)2NCHOH and the solution heated. Epichlorohydrin is thenadded 11 to cross-link the resin. Water is evaporated and the resin O OHis ground to the desired particle size. The reaction proceeds asfollows: m I

1015, in turn, 1s reacted with 1.2 moles of aniline-formal- (700E COOH 015 dehyde resin to yield a sequestering resin having a plural- C (CH:).-OH HG(CH1):CH ity of repeating units of the formula:

0 0 0H 0 0 OH O O OH O O OH O H NH: HCO(CH2)2O(OH2)2O--C-CHOH-(CH2)3CH Io 0 OH 0 0 0H OH; The resultant sequestering aldehyde then reacts Withthe I polyethylenimine to form a resin having repeating units of h l l te forrnu a {OH -CH -N Hr: OH

N-CHzCOOH CHzCOOH HOCH OH oooH CODE CH2CH2 N (CH2)aCH-CO(OH2)zO(CH2)2O-CH CH" C OOH C O O H C O OH Example 5 Theepichlorohydrin effects cross-linkage between ethylenelmme units nothaving a sequestering side chain there- Following h procedure f Example2 1 l f h On. The resultant 1011 exchange resin has excellentchesequestering agent lating properties. 0 O OH Example 3 i d i1(HOOCGH2)s-N-(CH2)z-OCH Ut1l1z1ng a proce ure slm ar to that of Example1, 1 40 COOH mole of the sequestering agent and 1.03 moles ofglutaraldehyde are reacted to form (HO O O GH2)2 2)z- 00011(H0OCCH2)zN-(CH2)zOC-CHOH(GH2)aH OOOH is reacted with 1.03 moles ofglyoxal to yield the product which in turn is reacted with 2 moles ofmelamine-alde- OH O hyde resin to yield a sequestering resin having aplurality u of repeating units of the formula (H O O C CHzhN-(GHQr-O(IE-CH n NHC O-NHOH: This, in turn, is reacted with 2 moles ofphenolformalde- ,1 H hyde resin (based on the monomers) to yield asequesteri ing resin having a plurality of repeating units of theformula: NH

|' on "l HCiJOH on coon CH (OHz)a-CH-CO(OH:)zN-(CH:O0OH): I

C O OH Example 6 HtJ-OH Following the procedure of Example 1, 2 moles ofthe sequestering agent 0-(OH2)1N(OH2COOH)2 OH (20013 HGOCHOHz-O CH2 0HCross-linking is then effected by adding excess formaldehyde andheating. O O OH are reacted with 1 mole of hexamethyl methylol melamine(hexamethoxy methyl melamine) to form which in turn is reacted with 1 /2moles of urea-formaldehyde resin to yield an insoluble ion exchangechelating resin having a plurailty of repeating units of the formula lCH3 as Well as other repeating units such as K ll Example 7 As analternate procedure 1 mole of phenol is reacted under controlledconditions With 1.8 moles of formaldehyde to provide aphenol-formaldehyde resin havingfree reactive methylol groups extendingfrom the polymer chain, such chain having a plurality of repeatinggroups of the formula l l Ion I r OH This, in turn, is reacted with 0.8mole of the sequestering agent to yield a sequestering resin having aplurality of repeating units of the formula OHz-O OOH Example 8 Example9 According to another procedure, 1.5 moles of lowmolecular weightphenol-formaldehyde (based on the monomers) is reacted with 1 mole ofthe sequestering agent ethylene diamine-diacetic acid. The resultantproduct is then cross-linked by the addition of heat and excessformaldehyde.

Example 10 Three moles of a relatively high molecular weightureaforrnaldehyde resin (based on the monomers) having free reactivemethylol groups extending from the polymer chain and having little or nocross-linkage is reacted with 2 moles of ethylene diamine triaceticacid. The resultant sequestering resin is divided into two parts. Thefirst part is further cross-linked under the action of heat and acid.Both portions function as excellent ion exchange resins although thefirst part is less soluble.

Example 11 The procedure of Example 1 is again carried out using 1 moleof the sequestering agent ethylene diamine di- (O-hydroxy-phenyl aceticacid) and 1.03 moles (based on the monomers) of low-molecular weightbutylatedformaldehyde-melamine having free reactive methylol groups asthe aldehyde-type compound. The product is then reacted Withphenol-formaldehyde polymer as described in Example 1.

Example 12 The procedure of Example 9 is carried out using 1 mole of thesequestering agent OOOH f. l and 2 moles of low-molecular weightphenol-formaldehyde to yield a resin having a plurality of the repeatingunits i011 (EH1 l l CH2 CHZCOOH l/ COOH N\ I CHr-UH-CH O This iscross-linked to an insoluble form by heating.

Example 13 The procedure of Example 1 is followed using as asequestering agent 1 /2 moles of as an aldehyde type compound 1 /2 molesof formaldehyde; and as an aldehyde-reactive resin a mixture of /2 moleof polyvinyl alcohol and 1 /2 moles of phenolformaldehyde resin. Theresultant sequestering resin is cross-linked and contains the repeatingunits:

Example 14 The procedure of Example 1 is followed using as asequestering agent /2 mole of as an aldehyde /2 mole of formaldehyde;and as a resin a mixture of /2 mole of phenol-formaldehyde resin andmole of polyethylenimine. The resultant sequestering resin iscross-linked and contains the repeating units:

L \CHPCHPT/ CH:

CHs-CHgand Example 15 The procedure of Example 1 is followed using 1mole of diethylene triamine tetracetic acid; 1.03 moles of acetaldehyde;and a 1.5 mole mixture of 30% polyvinyl alco hol and 70%phenol-formaldehyde (PVOH-P-F matrix).

Example 16 The procedure of Example 1 is followed using 1 mole of OH I(30011 as sequestering agent; 1.05 moles of glyoxal; and 1.6 moles of amixture of 50% methyl cellulose and 50% phenol-formaldehyde resin.

Example 17 The procedure of Example 1 is followed using 1 mole of aminodiacetic acid; 1.05 moles of formaldehyde; and 1.8 moles of a mixture of20% cellulose monoacetate and phenol-formaldehyde.

All the above examples produce ion exchange chelating resins ofexceptional chelating ability.

It will be obvious to those skilled in the art that various changes maybe made without departing from the spirit of the invention and thereforethe invention is not limited to what is described in the specification,but only as indicated in the appended claims.

What is claimed is:

1. A chelating resin comprising the reaction product of (A) an aldehydecompound having no more than 54 carbon atoms; (B) an aldehyde-reactivesequestering 13 14 agent containing at least one of the groups NH,wherein T is selected from the group consisting of --CH(COOH) and OHCOOH Y coon I I (|JH COOH and and having the formula J- cXY cXY cXY -Kwherein J is selected from the group consisting of i and wherein A, Band D are selected from the group 15 consisting of G OH wherein X isselected from the group consisting of 0003 OH OOOH H and (CH COOH;

wherein Y is selected from the group consisting of H H, SOOH and CH;CHzP OaHz, CHzSOs wherein a, b, and c are integers of from 0 to 1;wherein K is selected from the same group as I, but

15 a dlfierent member and Wherem and not more than one unit persequestering molecule E of -(CHY) -O--M among A, B and D; and (C) analdehyde-reactive Water-insolubilizable resin containing a plurality ofgroupings of the members F selected from the group consisting ofphenolic, imino,

, amino and hydroxyl, said aldehyde compound and are never m the samecompound forming a linkage between said resin and said gether;sequestering agent, the sequestering component of wherein E, F, and Gare selected from the group consisting of H, CH COOH, CH(COOH) -CH CHOH, CH CH OCH CH OH,

the resultant chelating resin being pendant as side chains from saidresin.

2. A chelating resin comprising the reaction product GB of (A) analdehyde compound selected from the group consisting of formaldehyde,acetaldehyde, glyoxyl, glu- OH 0H 7 I I taraldehyde, hexamethylolmelamine and pyruvic alde- (|JH hyde; (B) the sequestering agent 0 O OHHO 0 o 011,

I: \N(CH2)2 :INH

(CH SO H, (CH PO H and not more than HOOCCHE 1 one unit of and (C) aphenol formaldehyde-polyvinyl alcohol resin E matrix. H H 3. A chelatingresin comprising the reaction product 2C of (A) an aldehyde compoundselected from the group F consisting of formaldehyde, acetaldehyde,glyoxyl, g1utaraldehyde, hexamethylol melamine and pyruvic aldepersequestermg agent molecule; hyde; (B) the sequestering agent wherein Qis selected from the group consisting of OOOH H and OH I V 1 CH2 OH I ICHrN-OHa-CH; N0 (CHY)D 2 and (C) a phenol formaldehyde-polyvinyl alcoholresin matrix. wherein p is an integer of from 0 0 6O 4. A chelatingresin comprising the reaction product wherein M is selected from thegroup consisting of of (A) an aldehyde compound selected from the groupconsisting of formaldehyde, acetaldehyde, glyoxyl, glutaraldehyde,hexamethylol melamine and pyruvic aldehyde; (B) the sequestering agent(HOOCCH NH; and (C) phenol formaldehyde-polyvinyl alcohol matrix. D 5. Achelating resin comprising the reaction product of a resin having freereactive methylol groups and an aldehyde-reactive sequestering agentcontaining at least an one of the groups NH, CH(COOH) and 16 and havingthe formula 10. A chelating resin having a plurality of repeating J(CXY) units of the formula:

2. Where in I, X, Y, a, and K are the same as in claim 1, CHr-CHrN atleast some of said free reactive methylol groups react- 5 L HO CH OH00011 COOH ing with said sequestering agent to form a linkage betweensaid resin and said sequestering agent, the sequestering 2)aOH-CO(OH)zO(GH -OOH- component of the resultant chelating resin being pendantc0011 COOH as side chains from said resin.

6. A chelating resin having a plurality of repeating 1 11. A chelatingresin having a plurality of repeating units of the formula: units of theformula:

0 0 0 OH OH I n 1 CHrO-CHs l -CH:NGNH-- O-CH2-OHOCH L l .l N I I oH2--on, OH CH:

9 I N-O GH1O 1 y OH O 0 OH T 00 OH CH: N=C i HO-CH 1 OH 0-0Hz-OH-00H110-011 l H CH:

CH: NCHzO- C O OH HO O(OHz)2N(CH2COOH)a CH, O .CH;

12. A chelating resin having a plurality of repeating units of theformula:

7. A chelating resin having a plurality of repeating I l units of theformula: I

NH: l

CHg--- CH2 orb-000E OHzCOOH l/ N\ HOC CHa (CHz):OC-OOOH HCOH Hfl-COOHCHCOOH 13. A chelating resin having a plurality of repeating CHZOOOHunits of the formula: GHaCHz-N\ OH 8. A chelating resin having aplurality of repeating units of the formula:

CH1 CHQCOOH I l (10011 NH-C CNHCH:

L 2% J orn-t JH-cHr-o- OH IIIH HCOH OH 000B 14. A chelating resin havinga plurality of repeating (OHtk-CH-G-O-(CHzh-N-(CHgCOOH): units of theformula:

COOH I CHz-CH- L 1 l 9. A chelating resin having a plurality ofrepeating units of the formula: on, omooon 011 N(GH:)2O-CH CHzSOsHCHzCOOH CHz- 15. A chelating resin having a plurality of repeating unitsof the formula: f CH: I \CHPOHPT/ (3H2 CHzCHzOH L 00011 CODE NACHDPNCHzCOOH COOH 0CHzOH--CHs-O 6 16. A chelating res1n comprising thereaction product of (A) an aldehyde compound having no more than 54carbon atoms; (B) an aldehyde reactive sequestering and having theformula J(CXY) (CXY) (CXY) -K, wherein 1, X, Y, K, a, b and c are asdefined in claim 1; and (C) a phenolic resin containing hydroxyl groups,said aldehyde compound forming a linkage between said phenolic resin atat least some of said hydroxyl groups and said sequestering agent, thesequestering component of the resultant chelating resin being pendant asside chains from said resin.

17. A chelating resin comprising the reaction product of (A) an aldehydecompound having no more than 54 carbon atoms; (B) an aldehyde reactivesequestering agent containing at least one of the groups NH, -CH(COOH)and and having the formula J(CXY),,(CXY) (CXY) -K, wherein I, X, Y, K,a, b and c are as defined in claim 1; and (C) an aminoplast resin, saidaldehyde compound forming a linkage between said amiuoplast resin andsaid sequestering agent, the sequestering component of the resultantchelating resin being pendant as side chains from said resin.

18. A chelating resin comprising the reaction product of (A) an aldehydecompound having no more than 54 carbon atoms; (B) an aldehyde reactivesequestering agent containing at least one of the groups NH, CH(COOH)and and having the formula J(CXY) (CXY) (CXY) -K, wherein I, X, Y, K, a,b and c are as defined in claim 1; and (C) a polyol resin, said aldehydecompound forming a linkage between said polyol resin and saidsequestering agent, the sequestering component of the resultantchelating resin being pendant as side chains from said resin.

19. A chelating resin comprising the reaction product of (A) an aldehydecompound having no more than 54 carbon atoms; (B) an aldehyde reactivesequestering agent containing at least one of the groups NH, CH(COOH)and and having the formula l(CXY) (CXY) (CXY) K, wherein I, X, Y, K, a,b and c are as defined in claim 1; and (C) polyethyleneimine, saidaldehyde compound forming a linkage between said resin and saidsequestering agent, the sequestering component of the resultantchelating resin being pendant as side chains from said chelating resin.

24?. A chelating resin comprising the reaction product of (A) analdehyde compound having no more than 54 carbon atoms; (B) asequestering agent selected from the group consisting of C O OH OH and(C) an aldehyde-reactive Water-insulubilizable resin containing aplurality of groupings of the members selected from the group consistingof phenolic, imino, amino and hydroxyl, said aldehyde compound forming alinkage between said resin and said sequestering agent, the sequesteringcomponent of the resultant chelating resin being pendant as side chainsfrom said chelating resin.

References Cited by the Examiner Gregor, H. P., et al.: Ind. Eng. Chem.44, 2834-9 (1952), TPIASS. (Copy in Scientific Library.)

Hale: Research, vol 9 (1956), pp. 104-108, Butter- Worths ScientificPublications, London.

WILLIAM H. SHORT, Primary Examiner.

C. A. WENDEL, Assistant Examiner.

1. A CHLEATING RESIN COMPRISING THE REACTION PRODUCT OF (A) AN ALDEHYDECOMPOUND HAVING NO MORE THAN 54 CARBON ATOMS; (B) AN ALDEHYDE-REACTIVESEQUESTERING AGENT CONTAINING AT LEAST ONE OF THE GROUPS >NH, -CH(COOH)2AND